Structural frames (also referred to interchangeably herein as frame structures) have many uses. Bicycle frames are conventionally formed from a number of tubular members joined together in a suitable manner, as is well known. Other types of frames, used in bicycles for example, are also known. For example, by way of general background, U.S. Pat. No. 4,613,146 discloses a monocoque bicycle frame having a body defined by right and left side panels, top and bottom panels, and a bifurcated rearward portion defined by such panels and also by a rear wheel well insert. The body panels and insert completely enclose a continuous internal space which is compression loaded or tensile prestressed with a rigid foam plastic for increased torsional rigidity and resistance to impact distortion. The pedal sprocket and chain are both external of the hollow frame so as to not interrupt the continuity of the body cavity and its compression loading.